Sound-modulating device.



l. U. P'UIRIER.

SOUND MODULATING DEVICE.

APPLICATION mu) 1 mm. IQII.

2 SHEETS-SHEET 2.

1,237,81 3. Patented Aug. 21, um.

. INVEN'P OR WITNESSES J. U. POI rler QQMKQMQ, mfwg ilTornev PATENT OFFICE.

JOSEPH ULDERIC POIRIEB, OF MONTREAL, QUEBEC, CANADA.

SOUND-MODULATING DEVICE.

Application filed January 19, 1917.

The invention relates to improvements in;

sound modulatin devices for phonographs.

The object of t e invention is to modulate the volume of the sound at will by a cheap, sim 1e and efiicient device, andwhereby the 'qu'a ity of the sound will not' be affected,

owing to the special construction of the plunger, or modulating member.

'Another object of the invention is to prevent the vibrations from being abruptly interrupted and deflected backwardly to interfere with on coming vibrations when they strike the plunger, and this object is attained by, the particular inclination given to the working face of the said plunger. A further, object of the invention is to make the said plunger, in connection with the sound amplifyin device, resonant, in order to cause the sai plunger to vibrate in sympathy with the vibrations of the sound amplifier.

In the drawings, Figure 1 illustrates a vertical section through-the top portion of aphonograph of the cabinet type, provided with a concealed sound amplifier, showing the modulating device applied thereto.

Fig. 2 is an enlarged vertical section through a portion of the phonograph casing, showing a ortion of the casing and the sound am li er, and the plunger suitably se-l cured wit in its casing.

Fig. 3 is a vertical section through a portion of the cabinet of the casing of a phonograph showing a rear view of the sound ampliiier and modulating attachment.

Fig. 4 is an enlarged perspective view of the plunger or modulating member.

Like numerals of reference indicate corresponding parts in each figure.

Referring to the drawings, 1 is the casin of a talking machine, and 2 is the hinged specification of Letters Patent.

Patented Aug. 21, 1917.

Serial No. 143,306.

housing or cover. 3 is the top partition, secured below said cover, on which is mounted the swinging tone arm 4 provided with a reproducer 5. 6 is a turntable actuated by the usual motor 7.

Below the said partition 3, at a suitable distance, is provided a second or bottom partition 8, an 9 are doors to close the opening 10. Between the partitions 8 and 3 is suitably secured the sound amplifier 11, suitably curved in order to avoid contact with the motor 7, and provided at its smaller end with a vertical sound conductor 12 which is preferably secured at its inner or upper end to the under side of the partition 3 by the blocks 13, the said inner or upper end of said sound conductorcommunicating with the tone arm 4 the lower or outer end of said sound conductor being rigid] secured to the partition 8 by meansof the blocks 14.

The said sound amplifier 11 is preferably connected to said sound conductor 12 at an angle, and the sound conductor 12 is preferably rectangular in cross-section and hollow through and through and made of the same material as the sound amplifier and of the said sound amplifier and will form a continuation of the am lifier.

The top portion of sai plunger 15 is provided--with a transversecavity or channel 16 which is covered, by a curved plate 17,

l which is preferablymadeof the same material as the sound conductor 12 and. the sound amplifier 11, in.order that the vibrations caused by the air conducted through the said s'ound conductor may synchronize with the vibrations in the sound amplifier. The rear wall of the sound conductor 12 is provided at its lower or outer end with a longitudinal slot l8, and 19 is a screw secured to the lower end of said plunger 13 and projecting through said slot 18. 20 is a spring mounted on the outer projecting end of said screw 19, adapted to press outwardly on said screw in order to hold ti ht the plunger 15 in adjusted position wit in said sound conductor 12.

21 is a rod fulcrumed at 2'2 to the rear wall of the casin l and pivotally connected at its inner em? to the screw 19. The said rod 2i projects through an elongated Opening 23 in one side of the casing land terminates in a handle 24.

In the operation of the modulating device, it will readily be seen that in order to re.- duce the volume of tone without in any way impairing or interrupting the sound waves which are set into vibration by the reproducer, thehandle 24 of the rod 21- is pressed downward, thus raising the plunger 15 so that its upper end is caused to project into the amplifier, thus reducing the sound outlet in the sound conductor 12. The result is that the waves, or: strikin the curved surface will not be abruptly inter rupted and deliected backward but will simply deviate in their course into the sound amplifier 11 thus considerably reducing the resonance of the sound without altering any of its particular properties.

Such is not the case with the modulating devices which consist of a plate Introduce through the sound conductor at right angles to the direction of movement of the sound waves. These devices will' reduce the sound but the waves which strike against the said plate will be abruptly deflected and will interfere with the OII-COmll'lg wav es Another important feature of this invention consists in the particular construction of the plunger 15 which is provided with the elongated channel 16 covered by the plate 17. \Vhen the sound waves strike the plate 17 of the plunger, an equivalent resonance and similar vibrations to those of the amplifier will be obtained. Thus it will readily be seen that the quality of the tone will not be impaired in any way.

The said plunger can its sides with felt or an terial, in order that it will fit snugly within the sound conductor 12, and thus revent the mid plunger member from vi rating within said conductor.

What I claim is L In a talking machine, the combination, with a tone arm, anda sound conduit leading thereto; of an amplifier opening at an angle into the sound conduit; and a modulator movable bodily across the opening in said amplifier and having a deflecting surbe covered around other suitable ma-- face which is definitely disposed at an acute angle to the axis of the sound conduit whereby, when the modulator is projecte across soul opening, a tapered restriction is formed between the walls of the sound con- (lltllt and the deflecting surface of the moduator.

2. In a talking machine, the combin tion, with a tone arm, and a vertical soun conduit leading thereto at its iliner end; of an amplifier opening at an angle into the sound conduit between the ends of the latter; and a modulator slidable axially in said sound conduit-and havin a 'deficctin surface at its upper end whic is disp at an acute anggeltri thBb8 XJS of the conduit; said mo ua or em norma l?oscd m e lower portion of the sound con nit, but mb able upwardly so as to roject its upper and across the opening in 0 amp er, thereby to form a tapered restriction betweenithe walls oi the sound conduit and the deflecting surface of the modulator.-

In a talking machine, the combination, with a. tone arm, and a sound conduit leadmg thereto at its inner end and having its outer end portion provided with a. longitudipal slot; of an amplifier o g an e into said sound conduit b tween the inner end of the same and said slot; a modulator arranged in said sound conduit and having a deflecting surface which is at an acute angle to the axis of the conduit; said modulatpr being normally outer rnovab e axially therein toproject its deflect mg surface across the opcmng in the amplifier, thereby to form a tapered restriction between the walls of the sound congyit and the deflecting surface of the mod atorya member secured to said modulator and roecting outward 'th'rough'said slot; and an opcratin device connected to said p ecting meld i161 to efi'ect the movements 2? the modulator. y

4. In a talking machine, the combination, with a tone arm, and 9. sound conduit leading thereto; of an amplifier opening atan angle into the sound conduit; and a modulator in said sound conduit rovided at one a, resonant deend with a channel, and

'ng the seine and set at w: fleeting plate brid an acute angle to 0 axis of the sound conmachine, the combination, and a sound conduit leadof an amplifier opening at an no sound conduit; and a. moduladisposed in e lportion of said sound conduit, lzht V tor in said sound conduit provided at one end with a channel, and with a resonant deflecting plate which brid said channel and is set at an acute ange to the axis of the sound conduit; said modulator being slidable axially in said sound conduit so as to project said plate across the openin in the amplifier, thereby to form a. tapere re strictinn between the walls of the sound con- ;iuit and the deflelflflfimbhlmil,

atdr. 1 Signed at Montreal, Quebec, Uanada, this 13th dny of December, 1916.

JOSEPH ULDERIC POIRIER.

Witnesses:

F. AjBnsT, A .P. DEAL. 

